Tires have had the problem of early development of ozone cracking due to ozone in the air.
To address this problem, improvements to ozone crack resistance have been made by increasing the amount of antidegradants compounded into rubber compositions.
However increased amounts of antidegradants compounded into rubber compositions may result in tire products showing poor appearance due to color changes into brown during storage before sale. Thus, there has been a trade-off between ozone crack resistance (hereinafter simply “ozone resistance”) and discoloration resistance.
In an aim to provide rubber compositions which can suitably prevent ozone-induced degradation in a relatively high temperature region to provide excellent appearance, PTL 1 proposes rubber compositions which comprise 1.5 parts by weight or more of a petroleum paraffin wax based on 100 parts by weight of a diene rubber, wherein the petroleum paraffin wax comprises a C38-C40 linear saturated hydrocarbon and a C38-C40 branched saturated hydrocarbon in an amount of 10% by weight or more, with the amount of the branched saturated hydrocarbon being 19% by weight or more based on the total amount of the branched and linear saturated hydrocarbons.